Chemical resistant glass composition for fiberization



United States Patent 3,513,002 CHEMICAL RESISTANT GLASS COMPOSITION FOR FIBERIIZATION Dominick Labino, Grand Rapids, Ohio, assignor to Johns- Manville Corporation, New York, N.Y., a corporation of New York No Drawing. Filed Apr. 29, 1966, Ser. No. 546,178 Int. Cl. C03c 13/00, 3/08 US. Cl. 106-50 7 Claims ABSTRACT OF THE DISCLOSURE A glass composition of a specific combination of glass forming oxides providing improved chemical resistance and of working properties amenable for fiberization into glass fibers of improved durability and suitable for use in reinforced resin products, consisting essentially of: SiO B 0 A1 0 Na O; CaO; MgO; and, F and optionally K 0; B210; and ZnO.

This invention relates to a glass composition and, more particularly, to a novel andimproved glass composition for the manufacture of glass fibers.

Glass in a number of fibrous forms comprising staple fibers and continuous filaments or rovings, and in assorted woven and non-woven constructions or bodies, has over the years found a wide variety of uses and applications. One of the most significant and extensive areas of utility and service for typical glass fiber products has been in the reinforcement of resins and providing foundation or substratal components in resinous laminates and molded bodies. In this service, as well as in many others of its common fields of utility, glass fibers are often subjected to aggressive chemical conditions, particularly acid media. Moreover, the vulnerability of a glass composition to chemical attack is significantly dependent upon the extent of surface area exposed to the caustic elements or environment, and with the current, very fine glass fibers ranging down to submicron diameters, their susceptibility to corresion damage and degradation is therefore greatly multiplied.

It is the primary object of this invention to provide a new glass composition which is amendable to fiberization by conventional means or techniques, and possesses markedly improved chemical resistance.

It is also a primary object of this invention to provide improved glass fibers which are especially suitable for use in resin laminates, molded bodies and the like reinforced articles.

It is a further significant object to provide a relatively high silica content glass composition having low liquids temperatures and good working properties.

It is a specific and paramount object of this invention to provide a new glass composition which, is in the form of fine fibers or constructions formed thereof, is highly resistant to strong acids and the like aggressive acidic conditions or environments.

These and other objects and advantages, especially acid resistance, apparent from the hereinafter detailed description, are directly attributable to the concerted effects of the cooperation or interaction of a relatively narrow range of essential constituent oxide ingredients providing the new glass compositions of this invention. Specifically, the glass compositions of this invention in its broadest aspect consists essentially of those formed by the given components within the area or relatively proportions defined substantlally by the following percentages by weight thereof:

Ingredients: Ranges SiO 67.0-69.0 B203 5.5- A1 0 3.0- 5.0 Na O 10.0-14.0 K 0 0.0- 1.5 CaO 3.0- 6.5 MgO 0.5- 4.0 'BaO 0.0- 1.0 ZnO 0.0- 1.0 F 0.0- 1.5

Ingredients: Ranges SiO 68.0-69.0 B 0 5.8 6.0 A1 0 3.5- 4.5 Na O 11.0-13.0 K 0 0.5- 1.0 CaO 4.0- 6.0 MgO 2.0- 3.0 BaO 0.0- 0.5 ZnO 0.0- 0.5 F 0.0- 1.0

Aside from the pricipal objects and advantages of high acid resistance of this invention, glasses of the approximate range of formulation given provide melts with advantageous viscosity characteristics which render them particularly amenable to conventional fi-berizing means and techniques, comprising composition softening points in the order of 1300" F., and effective low liquids temperatures of about 1600 F. with minimum divitrification or formation of crystals during fiber formation and attenuation, thus permitting working of the molten to soft glass at temperatures in which crystals do not form. As such the glass compositions of this invention facilely fiberize with common means and apparatus into line diameter fibers of any commercial dimensions ranging down to submicron diameters, for example from approximately 25 micron through to approximately one half or less micron.

Following are specific examples of the glass compositions of this invention and of fibrous products thereof. These exemplary compositions are given for the purpose of illustration, and to demonstrate the pronounced improvements attributable to the compositions of this invention. The exemplary compositions or admixture of oxide ingredients forming the same and the method of producing the glasses or fibers thereof, and the properties of each, are not to be construed as limiting this invention to any specific compositions, means or conditions, etc., other than those set forth hereinbefore as essential.

3 EXAMPLE 1 The preferred specific glass composition of this invention consists of, in approximate percentages by weight:

pics from each acid solution following the hour exposure, and washing thoroughly, drying, etc. as in the previous test, the difference in the final weight from the original Weight of each specimen due to any acid attack was determined as the percentage lost. The loss of the pre g gj jii j fi %i Fif ferred composition of this invention exemplified by Ex- B2O3 5.9 ample 1 was 0.6% in weight whereas the loss in the A1203 4.1 prior art standard comprising the identified composition Nazo 11.9 of the Example III of No. 3,085,887 under identical con- KZO Q8 diti0ns was17.0%. cao AddltlOnfil specific examples lllustratin-g eifectlve acid Mgo 25 resistant glass compositions of this invention comprise Bao 0.2 in approximate percentages by welght the following:

ZnO 0.2 F2 Examples Ingredients 2 3 4 This glass exhibited the following composition proper- 1 0 ties of: 0 0 0 .0 0 5 .5 5

Softening point1320 F. Density-2.470 p.c.f. Liquidus1600 F.

Index of refracti0n1.5 10

Upon fiberizing by drawing a melt of the composition of Example 1 into continuous strands averaging about 000053 inch (approximately 13 microns) in diameter, the acid resistance thereof was determined and compared with that of a commercial E glass, the standard of the industry, which comprises the composition of U.S. Pat, S Oz 68.0-68.6 N0. 2,334,961, and also with a glass of the composition 2 5.9-6.0 Of Example 111 Of U.S. Pat. N0. 3,085,887. One gram A1 4.0-4.1 samples of continuous strands of like diameters of each N320 11.9-12.5 of these three glasses consisting of this invention com- K 0 0.0-0u8 prising the composition of Example 1 and the two prior C210 4.1-6.5 art compositions of the aforementioned patents, were re- MgO 0.5-2.9 spectively weighed and each placed in Erlenmeyer flasks BaO 00-02 with 200 cc. of the subsequently identified reagents diluted CnO 0.0-0 2 to the given concentrations. The flasks were marked for F 0.0-1.0 identification and each placed in a water bath at 205 F. 2. The chemical resistance glass composition of claim and held for the periods indicated. Upon expiration of the test periods, the remaining fibers were separated from the reagent by filtration and repeatedly washed with hot distilled water. The samples of residual fiber were then 1 in the form of fine fibers.

3. A glass composition of improved acid resistance consisting essentially of the following in approximate percentages by weight:

,fired to remove organic matter (filter paper), cooled in a 40 SiO 68.6 desiccator and weighed. The difference between the final B 0 5.9 weight and the original weight was determined and the A1 0 4.1 percentage loss due to the chemical attack was calculated Na O 11.9 and recorded in the following table. All pertinent data K 0 0.8 from the aforedescribed tests of each sample are set CaO 5.0 forth in the table below. MgO 2.6 A second sample of the glass composition of Example BaO 0.2 1 drawn and attenuated to substantially finer diameter ZnO 0.2 fibers averaging about 0.0002 inch (approximately 5 mi- F 0.7

TABLE -PRELIMINARY TEST H01 H01 H01 HCL H2804 H280 Glass 10% 10 a 10% 36.5% 10 50% Compositions 88.5 hr. 114 hr 336 hr. 336 hr. 336 hr 336 hr. E' Glass 47.2 44. 2. 67 No.3,085,887 42.5 43.4 43.7 38.0 4.90 .012 Example 1 4.10 1. 59 3.18 0. 44 1. 86 .0474

crons), and thus more susceptible to aggressive elements 4. The acid resistant glass composition of claim 3 in because of greater surface exposure, was also evaluated the form of fine fibers. in an acid environment and compared under identical 5. A glass composition of improved acid resistance in conditions with the same size very fine fibers of glass the form of fine fibers consisting essentially in percentages of the composition of Example III of U.S. Pat. No. by weight of: 3,085,887. S102 68.1 In this comparative examination, a one gram sample 7 E 0 6.0 of each the very fine fiber of the composition of Ex- A1 0 4.0 ample 1 above and of the said composition of No. Na O 12.5 3,085,887 were respectively dispersed in 300 ml. of 1 N CaO 6.5 sulfuric acid (H 80 and retained for one hour at boil- MgO 0.5

ing temperature. Upon recovering the residual fiber sam- F 6. A glass composition of improved acid resistance in the form of fine fibers consisting essentially in percentages -by weight of SiO 68.1 B203 A1203 4.0 Na O 12.5 CaO 4.2 MgO 2.9 F 1.0

7. A glass composition of improved acid resistance in the form of fine fibers consisting essentially in approximate percentages by weight of:

SiO 68.0 B203 6.0 15 A1 0 4.0 N3 0 12.5

References Cited UNITED STATES PATENTS 3/1959 Welsch 106-54 12/1961 De Lajarte 106-50 4/1963 Labino 10650 9/1962 Hagedorn 106-54 FOREIGN PATENTS 5/1964 Belgium.

HELEN M. MCCARTHY, Primary Examiner US. Cl. X.R 

